String.prototype.md5 = function() {

	var add32 = function(x, y) {
		var lsw = (x & 0xFFFF) + (y & 0xFFFF);
		var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
		return (msw << 16) | (lsw & 0xFFFF);
	};

	var bitrol = function(n, c) {
		return (n << c) | (n >>> (32 - c));
	};

	var cmn = function(q, a, b, x, s, t) {
		return add32(bitrol(add32(add32(a, q), add32(x, t)), s),b);
	};

	var ff = function(a, b, c, d, x, s, t) {
		return cmn((b & c) | ((~b) & d), a, b, x, s, t);
	};

	var gg = function(a, b, c, d, x, s, t) {
		return cmn((b & d) | (c & (~d)), a, b, x, s, t);
	};

	var hh = function(a, b, c, d, x, s, t) {
		return cmn(b ^ c ^ d, a, b, x, s, t);
	};

	var ii = function(a, b, c, d, x, s, t) {
		return cmn(c ^ (b | (~d)), a, b, x, s, t);
	};

	var pack = function(b) {
		var l = b.length << 2;
		var s = new Array(l);
		for (var i = 0; i < l; i++) {
			s[i] = String.fromCharCode((b[i >> 2] >>> ((i % 4) << 3)) & 255);
		}
		return s.join("");
	};

	var unpack = function(s) {
		var l = s.length;
		var b = new Array();
		for (var i = 0; i < l; i++) {
			b[i >> 2] |= (s.charCodeAt(i) & 0xff) << ((i % 4) << 3);
		}
		return b;
	};

	var x = unpack(this);
	var len = this.length << 3;
	x[len >> 5] |= 0x80 << ((len) % 32);
	x[(((len + 64) >>> 9) << 4) + 14] = len;

	var a =  1732584193;
	var b = -271733879;
	var c = -1732584194;
	var d =  271733878;

	for (var i = 0; i < x.length; i += 16) {
		var olda = a;
		var oldb = b;
		var oldc = c;
		var oldd = d;

		a = ff(a, b, c, d, x[i+ 0], 7 , -680876936);
		d = ff(d, a, b, c, x[i+ 1], 12, -389564586);
		c = ff(c, d, a, b, x[i+ 2], 17,  606105819);
		b = ff(b, c, d, a, x[i+ 3], 22, -1044525330);
		a = ff(a, b, c, d, x[i+ 4], 7 , -176418897);
		d = ff(d, a, b, c, x[i+ 5], 12,  1200080426);
		c = ff(c, d, a, b, x[i+ 6], 17, -1473231341);
		b = ff(b, c, d, a, x[i+ 7], 22, -45705983);
		a = ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
		d = ff(d, a, b, c, x[i+ 9], 12, -1958414417);
		c = ff(c, d, a, b, x[i+10], 17, -42063);
		b = ff(b, c, d, a, x[i+11], 22, -1990404162);
		a = ff(a, b, c, d, x[i+12], 7 ,  1804603682);
		d = ff(d, a, b, c, x[i+13], 12, -40341101);
		c = ff(c, d, a, b, x[i+14], 17, -1502002290);
		b = ff(b, c, d, a, x[i+15], 22,  1236535329);

		a = gg(a, b, c, d, x[i+ 1], 5 , -165796510);
		d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
		c = gg(c, d, a, b, x[i+11], 14,  643717713);
		b = gg(b, c, d, a, x[i+ 0], 20, -373897302);
		a = gg(a, b, c, d, x[i+ 5], 5 , -701558691);
		d = gg(d, a, b, c, x[i+10], 9 ,  38016083);
		c = gg(c, d, a, b, x[i+15], 14, -660478335);
		b = gg(b, c, d, a, x[i+ 4], 20, -405537848);
		a = gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
		d = gg(d, a, b, c, x[i+14], 9 , -1019803690);
		c = gg(c, d, a, b, x[i+ 3], 14, -187363961);
		b = gg(b, c, d, a, x[i+ 8], 20,  1163531501);
		a = gg(a, b, c, d, x[i+13], 5 , -1444681467);
		d = gg(d, a, b, c, x[i+ 2], 9 , -51403784);
		c = gg(c, d, a, b, x[i+ 7], 14,  1735328473);
		b = gg(b, c, d, a, x[i+12], 20, -1926607734);

		a = hh(a, b, c, d, x[i+ 5], 4 , -378558);
		d = hh(d, a, b, c, x[i+ 8], 11, -2022574463);
		c = hh(c, d, a, b, x[i+11], 16,  1839030562);
		b = hh(b, c, d, a, x[i+14], 23, -35309556);
		a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
		d = hh(d, a, b, c, x[i+ 4], 11,  1272893353);
		c = hh(c, d, a, b, x[i+ 7], 16, -155497632);
		b = hh(b, c, d, a, x[i+10], 23, -1094730640);
		a = hh(a, b, c, d, x[i+13], 4 ,  681279174);
		d = hh(d, a, b, c, x[i+ 0], 11, -358537222);
		c = hh(c, d, a, b, x[i+ 3], 16, -722521979);
		b = hh(b, c, d, a, x[i+ 6], 23,  76029189);
		a = hh(a, b, c, d, x[i+ 9], 4 , -640364487);
		d = hh(d, a, b, c, x[i+12], 11, -421815835);
		c = hh(c, d, a, b, x[i+15], 16,  530742520);
		b = hh(b, c, d, a, x[i+ 2], 23, -995338651);

		a = ii(a, b, c, d, x[i+ 0], 6 , -198630844);
		d = ii(d, a, b, c, x[i+ 7], 10,  1126891415);
		c = ii(c, d, a, b, x[i+14], 15, -1416354905);
		b = ii(b, c, d, a, x[i+ 5], 21, -57434055);
		a = ii(a, b, c, d, x[i+12], 6 ,  1700485571);
		d = ii(d, a, b, c, x[i+ 3], 10, -1894986606);
		c = ii(c, d, a, b, x[i+10], 15, -1051523);
		b = ii(b, c, d, a, x[i+ 1], 21, -2054922799);
		a = ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
		d = ii(d, a, b, c, x[i+15], 10, -30611744);
		c = ii(c, d, a, b, x[i+ 6], 15, -1560198380);
		b = ii(b, c, d, a, x[i+13], 21,  1309151649);
		a = ii(a, b, c, d, x[i+ 4], 6 , -145523070);
		d = ii(d, a, b, c, x[i+11], 10, -1120210379);
		c = ii(c, d, a, b, x[i+ 2], 15,  718787259);
		b = ii(b, c, d, a, x[i+ 9], 21, -343485551);

		a = add32(a, olda);
		b = add32(b, oldb);
		c = add32(c, oldc);
		d = add32(d, oldd);
	}

	return pack([a, b, c, d]);
}

